1. Field of the Invention
The present invention relates to the separation of hydrogen peroxide from methyl benzyl alcohol oxidate by water and ethyl benzene extraction.
2. Description of the Prior Art
Hydrogen peroxide is an important chemical of commerce which is produced in very large quantities for use in a number of industrial applications. The predominant process used commercially for the production of hydrogen peroxide involves the oxidation of anthrahydroquinone, extraction of hydrogen peroxide and reduction of the resulting anthraquinone to anthrahydroquinone which is reused. This process requires very high capital expenditures in that use of a working solvent with efficient recycle of various process components is a necessity.
Substantial efforts have been directed to processes which involve direct combination of hydrogen and oxygen but thus far such processes have not found widespread success.
Hydrogen peroxide has been formed by the oxidation of secondary alcohols. At one time the production of hydrogen peroxide by oxidation of isopropanol was practiced commercially. Other secondary alcohols which have been mentioned as starting materials for hydrogen peroxide production include 1-phenyl ethanol (methyl benzyl alcohol) and cyclohexanol. See, for example, U.S. Pat. Nos. 2,871,102-4 of Shell Development. In such prior procedures, difficulties have been encountered in the separation and recovery of product hydrogen peroxide from the secondary alcohol oxidate mixtures. See, for example, Shell U.S. Pat. Nos. 2,819,949, 2,869,989, 2,949,343, 3,003,853, 3,012,860 and 3,074,782.
Hydrogen peroxide has also been formed by oxidation of very high boiling secondary alcohols such as diaryl methanol, the product hydrogen peroxide being stripped from the reaction mixture during oxidation; see U.S. Pat. No. 4,303,632.
In certain commercial technologies, there are produced substantial quantities of various secondary alcohols. For example, in the coproduction of propylene oxide and styrene monomer by the reaction of ethyl benzene hydroperoxide with propylene, methyl benzyl alcohol is formed and ultimately converted by dehydration to styrene monomer. See U.S. Pat. No. 3,351,635.
In U.S. Pat. No. 4,897,085, a process is described for the production of hydrogen peroxide by oxidation of methyl benzyl alcohol containing streams, such as those formed in the Oxirane process.
In U.S. Pat. No. 4,897,252, a process for the recovery of hydrogen peroxide from methyl benzyl alcohol oxidation mixtures by ethyl benzene extraction is described. The present invention provides a further improvement in this process.